Effects of Developmental Stage and Transitions on Drug Use trajectories Project Description: The major goal of the proposed study is to investigate the effects of developmental stage and transitions on drug use trajectories, with implications for designing prevention programs for the emerging adulthood and early adulthood periods, a relatively understudied population for prevention. Using data collected on a large urban population-representative sample (N=1206, 50% female, 40% low-moderately low income, 75% white) from a longitudinal randomized substance use prevention trial, the study will conduct secondary data analyses to understand shifts in drug use risk and variables predictive of these shifts over four different developmental periods: early adolescence (P1: middle school, or age 12-14), late adolescence (P2: high school, or age 15-18), emerging adulthood (P3: age 19-25) and adulthood (P4: older than age 25), with a particular focus on the impact of emerging adulthood transitions as moderators of drug use. The proposed study will also determine whether mediating variables, especially those targeted by the intervention program, that have been previously found to affect drug use risk through the adolescent years have a sustained mediational relationship to drug use in adulthood, and whether these same variables are associated with emerging adulthood transitions. The aims of the proposed project are: 1. To examine the growth trajectories of substance use in a series of developmental periods from early adolescence to adulthood;2. To identify protective and risk factors associated with the growth trajectories of substance use during different developmental periods;3. To investigate moderation impacts of age/stage-based transition, social life event transition and environmental life event transition on substance use behavior during emerging adulthood;and an exploratory Aim 4. To identify subgroups of individuals with more salient drug use risk trajectories from early adolescence to emerging adulthood. State-of-the-art as well as new exploratory variations of growth curve modeling will be used to test these relationships. The study is expected to yield important directions for developing booster and tailored prevention programs for young adults who are identified by shifts in drug use risk. The findings should generalize to young adult populations from urban areas. PUBLIC HEALTH RELEVANCE: The present project focuses on increasing our understanding of the relationships of substance use and risk trajectories to developmental stages and transitions, over a life span covering early adolescence to early adulthood (from age 11 to 30). The proposed study will use a longitudinal randomized prevention trial data set with 14 waves of data collected between 1987 and 2005 to investigate the relationships of substance use trajectories in different developmental periods and identify critical factors associated with substance use at each period. Findings are expected to inform the development of targeted prevention programs for young adults, a population relatively understudied in prevention, and thus potentially constituting a specialized health disparities group.